I also witnessed a horrible accident at my range yesterday. A guy shooting Hornady 460 Magnum rounds out of a revolver decided to hold onto the front of the cylinder to steady the gun when he fired it. The hot gasses from the round discharge severed his thumb and almost severed his finger too. The 460 round is enormous, and packs a lot of powder! The blood-splatter was impressive to say the least, it would have been worse if most of the wound hadn't been cauterized by the powder-burns. I can't even imagine the pain involved. His hand is permanently maimed. It happened on the first round fired, and he was sitting right next to me, in fact the round he fired went into my target as he flinched.
Google magnum 460. It's larger than a 50cal round. I can't imagine why anyone would even want to shoot it.